The damn fuel pump issue.....

[SBR70.3]

Did you get the filter you will need it because it doeaent have filter socks on it

Yes, I did. I'll definitely ask for help if I need it.

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[SBR70.3]

KPM800 arrived on Saturday and I installed it yesterday. Install was not difficult at all. Took my car for a spirited drive and had no hiccups when revving it to 7,500 RPM on multiple occasions. The real test will be Aug 15th for my next track day.

 

[K Myers]

Im running the KPM 1000 and love it where did you mount your fuel filter

 

[SBR70.3]

Im running the KPM 1000 and love it where did you mount your fuel filter

There is a small hole on the fender just under the strut tower brace. I used one of the bolts to mount it there, but I will likely end up drilling 2 holes in the K member or strut tower brace to attach it there.

 

[John S]

I sliced off the unused sound tube tab on the shock tower and made a simple bracket to mount the large Radium Filter. There's even a weld-nut and hole perfectly placed on the shock tower to aid installation. Access to the dip stick is maintained and the filter tucks under the cowl/strut brace. I don't like the idea of mounting the filter in a hot engine compartment but it's so practical compared to an underbody project plus my hood is vented and I feel a little more comfortable with the Russell braided fuel lines over the OEM style plastic plumbing.

 

[SBR70.3]

I sliced off the unused sound tube tab on the shock tower and made a simple bracket to mount the large Radium Filter. There's even a weld-nut and hole perfectly placed on the shock tower to aid installation. Access to the dip stick is maintained and the filter tucks under the cowl/strut brace. I don't like the idea of mounting the filter in a hot engine compartment but it's so practical compared to an underbody project plus my hood is vented and I feel a little more comfortable with the Russell braided fuel lines over the OEM style plastic plumbing.

That looks good. The mounting hole on my 2021 is horizontal. I don't think I have a vertical hole, but I'll look when I get home. Did you reinstall the K brace and strut tower brace?

 

[horsepower addiction]

Supplying enough fuel for a drag car or occasional street blasts is completely different from top speed runs and track days, especially with long sweepers. Keeping the bucket “full” is basically optional for street and drag use.

Generally you want to keep the bucket full all the time in all driving conditions. This helps keep the fuel pump cool and insures you don’t starve the system of fuel.

 

[horsepower addiction]

When you install the new pumps make sure you get any air out of the tube that crosses over from one side of the tank to the other. If air gets trapped in there it acts like a toilet trap and slows down fuel transfer across the tank

 

[engineermike]

Generally you want to keep the bucket full all the time in all driving conditions. This helps keep the fuel pump cool and insures you don’t starve the system of fuel.

Ideally yes and I completely agree, but next to no one with a modded Mustang can claim theirs does that.

Under hard cornering or with less than about 1/3 tank of gas, the bucket is only filling from one saddle. I’ve tested the fill rates and can tell you that only a stock gen3 on gasoline is capable of keeping the bucket full from one side at max power. A stock gen2 or gt350 won’t. Convert any of them to e85 or add a supercharger and the consumption rate is faster than the single-sided fill rate. I tested these bucket fill rates myself.

The grace is the bucket “capacitance” gives you some time at wot before the pump is starved, and *usually* that gets you well past a quarter mile and 140+ mph.

 

[John S]

make sure you get any air out of the tube that crosses over from one side of the tank to the other.

How, I reconnected the crossover into the KPM adapter fitting without thinking about it.

Did you reinstall the K brace and strut tower brace?

Both braces are going back on after other mods are finished.

 

[SBR70.3]

Convert any of them to e85 or add a supercharger and the consumption rate is faster than the single-sided fill rate. I

I can confirm this. Have you done any testing on the KPM unit? I will do my official testing on the 15th and give a report.

 

[engineermike]

Have you done any testing on the KPM unit?

I have not.

 

[John S]

I will do my official testing on the 15th and give a report.

Good luck, hoping all goes well.

 

[horsepower addiction]

Ideally yes and I completely agree, but next to no one with a modded Mustang can claim theirs does that.

Under hard cornering or with less than about 1/3 tank of gas, the bucket is only filling from one saddle. I’ve tested the fill rates and can tell you that only a stock gen3 on gasoline is capable of keeping the bucket full from one side at max power. A stock gen2 or gt350 won’t. Convert any of them to e85 or add a supercharger and the consumption rate is faster than the single-sided fill rate. I tested these bucket fill rates myself.

The grace is the bucket “capacitance” gives you some time at wot before the pump is starved, and *usually* that gets you well past a quarter mile and 140+ mph.

You not wrong.
I wouldn’t recommend doing any hard driving with 1/3 tank. The Venturi sucks fuel ungodly slow and the little hole in the bottom of the bucket that fills it isn’t much better. Transfer from the side without the pump to the side with slows way down as the tank gets low because the siphon stops and it relies on the Venturi. This happens because where the fuel enters the bucket from the other is almost at the top of the bucket. The top line is where the fuel enters the bucket so when fuel gets close to this level the siphon is pretty much useless. You can modify the bucket to keep the siphon going longer and stronger buy making a hole lower down closer to the Venturi where the lower line is.
If someone changes the pump and don’t know what there doing and they get air in the line from one side to the other the siphon no longer works and it relies on the Venturi completely.
The black dot is the valve that allows fuel to enter the bucket when fuel is below the top of the bucket. I run two 525 pumps so I installed a 3/4” one in my bucket. I also no longer have a Venturi system. The little hose just keeps my bucket full. I have a second bucket in the other side of the tank. When fuel on the primary side is below the set point the pump turns on transferring fuel across into my primary side until the level is above set point keeping fuel above the bucket. If fuel on the other side is too low the pump will not turn on

 

[engineermike]

I wouldn’t recommend doing any hard driving with 1/3 tank.

Maybe, but you said "you want to keep the bucket full all the time in all driving conditions" which would include WOT at 1/3 tank of fuel because that is a plausible driving condition.

The Venturi sucks fuel ungodly slow

The stock Gen3 bucket and venturi system pulls fuel from the passenger's side at about 150 lph and from the driver's side at about 220 lph. The stock Gen3 consumes about 135 lph at WOT on gasoline. This is why I said that the purely stock Gen3 will sustain any scenario, even WOT at low fuel in hard cornering without even relying on bucket capacitance.

Transfer from the side without the pump to the side with slows way down as the tank gets low because the siphon stops and it relies on the Venturi. This happens because where the fuel enters the bucket from the other is almost at the top of the bucket. The top line is where the fuel enters the bucket so when fuel gets close to this level the siphon is pretty much useless.

The venturi does all the heavy lifting for transferring fuel from the PS.

You can modify the bucket to keep the siphon going longer and stronger buy making a hole lower down closer to the Venturi where the lower line is.

Both venturi jets empty into the top of the bucket for a reason. This is to de-gas the fuel. Either venturi can pull air in, but mainly the PS. If the fuel is low, the venturi basically empties the PS saddle into the DS, after which is simply pulls air in which is sent to the bucket. But since it enters the top of the bucket, deflected down by an umbrella of sorts, the air is allowed to escape. If you inject this air into the bottom of the bucket, you now have aerated fuel being pulled into the pump(s).

If someone changes the pump and don’t know what there doing and they get air in the line from one side to the other the siphon no longer works and it relies on the Venturi completely.

The system is designed to purge air from the crossover line. If not, it would become vapor locked any time you're below about 1/4 tank because the venturi jet pump will pull air in.

The black dot is the valve that allows fuel to enter the bucket when fuel is below the top of the bucket.

That's the mushroom valve and its only purpose is to allow the bucket to fill during refueling. I measured the flow of it as well and it's negligible.

...The little hose just keeps my bucket full.

Where does the little hose get fuel from?

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